LTE Advanced

About: LTE Advanced is a research topic. Over the lifetime, 4055 publications have been published within this topic receiving 74262 citations. The topic is also known as: Long-Term Evolution Advanced & LTE-A.

Contention-based transmission with contention-free feedback for reducing latency in lte advanced networks and enhanced pucch

Abstract: Methods for contention-based transmission with contention-free feedback for reduced latency in LTE Advanced networks and an enhanced PUCCH are generally disclosed herein. User equipment (UE) may transmit a contention sequence on a physical uplink control channel (PUCCH) to an enhanced-Node B (eNB) and may concurrently transmit data requesting uplink resources on a physical uplink shared channel (PUSCH) to the eNB. The contention sequence is transmitted on the PUCCH in accordance with a format that is assigned by the eNB. The contention sequence is either randomly selected by the UE or assigned by the eNB. When the contention sequence and data are not successfully received by the eNB, the UE may fall back to a more conventional random access channel (RACH) procedure for uplink resource allocation.

A Software Defined Radio based implementation of the “Tower Overlay over LTE-A + ” system

Abstract: The basic idea of the “Tower Overlay over LTE-A+” system (TOoL+) is to offload popular services, especially live video, from cellular networks, thereby decreasing the operational cost of such networks. This can be realized by using High Tower High Power (HTHP) transmitters whose signals can be seen as an overlay to the cellular networks. For the integration of HTHP signals into the cellular networks, the Carrier Aggregation (CA) mechanism known from LTE-A is used. Future Extension Frames (FEFs) provided by the terrestrial broadcast standard DVB-T2 are used to generate a time-division multiplex of signals according to either DVB-T2 or LTE-A. This approach provides a backward compatible migration path from classical TV broadcast to TOoL+ as well as co-operative spectrum usage and the reuse of existing transmitter sites. After introducing the proposed system, this paper presents a demonstrator to show the technical feasibility of the concept. This demonstrator is based on the flexible Software Defined Radio (SDR) approach and covers both a Hybrid Modulator, an unmodified TV set and a prototype of an LTE-A+ terminal.

Range expansion for pico cell in heterogeneous LTE — A cellular networks

Abstract: In LTE-Advanced, a heterogeneous network (HetNet) where femtocells and picocells overlaid onto macrocells is extensively discussed in addition to traditional well-planned macrocell deployment to improve further the system throughput. recently, the Pico cell range expansion (CRE) in the Heterogeneous Cellular Networks has received a great attention. Thus, Pico cells are added to a macro-cell layout aiming for benefiting average system throughput from cell-splitting. Considering that the large coverage of macro cell can limit the cell-splitting gains, cell range expansion (CRE) is employed to increase the fraction of UEs camped on pico cells. However, some pico user equipments (UEs) suffer from macro cells due to cell range extension. In this paper, we proposed the path loss from macro eNodeB (MeNB) using large downlink reference signals received power (DL-RSRP), with various bias values to increase coverage and capacity for the Pico cell, to associate much user equipment for Pico base station. In our experiments, show that the proposed scheme can remarkably improve cell edge spectral efficiency as well as overall system capacity.

Seamless voice over LTE

Abstract: Long Term Evolution (LTE) as an evolution of fourth generation (4G) technology offers high data rate of upto 100 Mbps for data applications. But it lacks native support for Circuit Switched (CS) voice service which has been the main revenue generator for operators. This introduces the problem of how to provide voice call when a user is in LTE and how to ensure voice call continuity when it moves out of LTE coverage. There are possible technical solutions e.g CS fallback, Single Radio Voice Call Continuity (SRVCC), Voice over LTE via Generic Access (VoLGA), third party services like skype for providing voice call and voice call continuity over LTE. The paper compares various aspects of these solutions and suggests possible roadmap that operators can adopt to provide seamless voice over LTE.

Modelling and analysis of vertical handover in highly mobile environments

Abstract: Various types of wireless networks have been developed and deployed including 3G, WLAN, WiMAX, LTE and LTE Advanced. User connectivity and network performance can be improved using vertical handover techniques which involve switching between available networks in heterogeneous environments. In this respect, recently there has been an increased interest in the integration of cellular and WLAN systems. In this study, the integrated heterogeneous wireless systems are modelled using two-stage open queuing systems. The proposed analytical model builds a framework for acceptable levels of QoS in heterogeneous environments. This paper gives the detailed analysis of the integrated cellular/WLAN systems based on the deployment of guard channels and buffering at base station for highly mobile users in the cellular systems. Numerical results are obtained using the exact spectral expansion solution approach. These results are then analysed in terms of operational spaces and are shown to be useful for vertical handover decision management.